The invention relates generally to medical devices and methods, and more particularly to medical devices and methods for injecting high viscosity dermal fillers into a body.
High viscosity medicaments, such as dermal fillers, can be injected into the body to augment soft tissue portions within the body. For example, high viscosity compositions can be injected adjacent the urinary sphincter muscle to increase the volume of the tissue within the urinary tract to treat urinary incontinence. High viscosity compositions can also be injected into the skin to change the contour of and/or increase the volume of the skin. For example, known high viscosity compositions can be injected within facial skin to remove wrinkles, treat scars or the like.
Some known procedures for injecting high viscosity dermal fillers include injecting the dermal filler using a standard syringe. In such procedures, the force and/or pressure required to convey the dermal filler from the syringe body through the needle can be generated manually by having the user manually depress a plunger into the syringe body. The force generated by manually depressing a plunger, however, can be sporadic, thus resulting in undesirable fluctuations in the flow of the dermal filler through the needle, which can result in the user injecting more or less dermal filler at a particular location within the body than is desired. Generating the injection force and/or pressure manually can also result in inconsistent results between different users. Moreover, in certain situations, the force generated by manually depressing a plunger can be insufficient to provide the desired flow rate of dermal filler. Additionally, because the total volume of dermal filler injected is a function of the length of travel of the plunger, it can be difficult to deliver a sufficient volume of dermal filler when injecting the dermal filler manually using a standard syringe. Moreover, generating the injection force and/or pressure manually can result in user fatigue and/or chronic health problems for the user, such as, for example arthritis.
Thus, a need exists for improved apparatus and methods for injecting high viscosity dermal fillers into a body.